It's certainly not a bad place to raise a family, but if ideal is the standard (and we're comparing it to other places in Dutchess County), then I'm not sure. Safety would have to be a chief concern of parents, and though Beacon's crime stats are pretty reasonable, they're still a little more elevated than other areas of Dutchess, such as eastern towns like Pawling or Dover.
The good thing about Beacon is that it's not far from things to do (as in, family activities) and it has culture, but it's also not the quietest place in the county to raise a family. It's not as active as Poughkeepsie, though.
It all really depends on that for which you're looking. I know many families who thrived in Beacon, even taking into account the things I just said. If you want a sleepier town to raise kids, though, then this probably isn't it.
